Solvent-free [Ru]-catalyzed isomerization of allyl glycidyl ether: The scope, effectiveness and recycling of catalysts, and exothermal effect

Abstract

The effectiveness of selected simple ruthenium catalyst precursors, mainly [RuClH(CO)(PPh3)3] and {[RuCl2(p-cymene)]2}, in the solvent-free isomerization of a model allyl glycidyl ether (AGE) into a 1-propenyl derivative has been examined. The high throughput screening experiment method was adopted for the investigation of the catalytic activity of ruthenium complexes under various reaction conditions. The presence and amount of allyl hydroperoxides were recognized to be crucial for this reaction. For the first time it was found that the neat {[RuCl2(p-cymene)]2} displayed a high catalytic activity in the isomerization of the AGE containing allyl hydroperoxides. The real effectiveness and the recycling of the selected ruthenium catalyst, neat or coupled with some additives such as bases and/or the hydride ligand donor, have been evaluated under various conditions. The method can also be readily scaled up without any practical problems. New, technologically significant facts, important for the assessment of the process reliability have been discovered.